The Pakistan army says it has killed more than 50 militants in an operation to halt a push by Taliban militants toward the capital Islamabad.

Army spokesman Maj. Gen. Athar Abbas also said Wednesday that one member of the security forces was killed and more than 50 others abducted in the fighting in the Buner region.

Helicopter-borne commandos secured a key town from the Taliban on Wednesday as warplanes pounded militants to halt their advance toward the Pakistani capital, the army said.

Pakistan is acting under intense U.S. pressure to take a tougher line against Islamist militants expanding from strongholds along the Afghan border, where Al Qaeda leaders including Usama bin Laden may also be hiding.

In recent days, government forces have begun trying to drive the Taliban back into the Swat Valley, from where they had pushed out under cover of a creaking peace pact struck in February.

Helicopters dropped troops near Daggar, the main town in the Buner district, and in neighboring areas early on Wednesday morning, an army statement said.

The commandos secured the town and were linking up with police and paramilitary troops already in the area, the statement said.

It didn't say how many troops were involved or whether they clashed with militants who overran the district earlier this month.

However, a Pakistani military official said army jets and helicopters had attacked militant positions in the area as part of the move to take Daggar.

The official asked for anonymity because he was not authorized to release the details. He had no word on any casualties from Wednesday's operation.

The Taliban advance into Buner brought them to within 60 miles of the capital, Islamabad.

Troops are also battling militants in Dir, another area neighboring Swat.